Genetic variation blocks exercise’s positive effects on metabolism

Washington, DC—As many as one in five people with Type 2 diabetes do not see any improvement in blood sugar management when they engage in a supervised exercise regimen, according to a new scientific review published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism.

People develop Type 2 diabetes when their bodies become resistant to the hormone insulin, which carries sugar from the blood to cells. This leads to excess sugar in the bloodstream. The U.S. Centers for Disease Control and Prevention projects about 40 percent of Americans will develop diabetes within their lifetime.

“Since obesity and lack of physical activity are two key risk factors for Type 2 diabetes, physicians frequently recommend exercise and other lifestyle interventions to prevent or manage the disease,” said one of the study’s authors, Lauren Marie Sparks, PhD, of Florida Hospital and the Sanford-Burnham Medical Research Institute in Orlando, FL. “Most people benefit from an exercise regimen, but our research indicates that a significant minority of individuals with Type 2 diabetes do not experience the same improvements in metabolism due to their genes.”

The scientists examined clinical studies where people with Type 2 diabetes participated in exercise regimens, as well as animal and genetic studies on the topic.

The researchers found that around 15 percent to 20 percent of individuals with Type 2 diabetes did not see any improvement in their blood sugar control, insulin sensitivity or a measurement of fat-burning capabilities called muscle mitochondrial density. Genetic and animal studies indicate this resistance to exercise is encoded in DNA and can be handed down through generations.

“More research is needed to determine which people with or at risk of developing Type 2 diabetes will respond to an exercise program and which will not,” Sparks said. “Genetic and epigenetic patterns could hold the key to differentiating between the two groups. With that information in hand, we can target specific interventions and treatments to the individuals who will benefit most and identify novel treatment approaches to help those who do not respond to exercise.”

The study was co-authored by Natalie A. Stephens, PhD, of the Translational Research Institute for Metabolism and Diabetes at Florida Hospital.

The study, “Resistance to the Beneficial Effects of Exercise in Type 2 Diabetes: Are Some Individuals Programmed to Fail?”, was published online, ahead of print.

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Founded in 1916, the Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, the Endocrine Society’s membership consists of over 18,000 scientists, physicians, educators, nurses and students in more than 122 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Washington, DC. To learn more about the Society and the field of endocrinology, visit our site at www.endocrine.org. Follow us on Twitter at https://twitter.com/#!/EndoMedia.